<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- <input type="text" id="ab">+
    <input type="text" id="bc">=
    <span id="ss">0</span>
    <button onclick="btn()">结果</button>

    <script>
        function btn() {
            var ab = document.getElementById("ab").value;
            var bc = document.getElementById("bc").value;
            var ss = document.getElementById("ss");
            console.log(ab+"+"+bc);
            ss.innerText = eval(ab+"+"+bc);
        }
    </script> -->
    <!-- <input type="text" id="a">+
    <input type="text" id="b">=
    <span id="c">0</span>
    <button onclick="d()">结果</button>

    <script>
        function d(){
            var a=document.getElementById("a").value;
            var b=document.getElementById("b").value;
            var c=document.getElementById("c");
            // console.log(a+"+"+b)
            c.innerText=eval(a+"+"+b);
        } -->

        <!-- <input type="text" id="d">+
        <input type="text" id="q">=
        <span id="d">0</span>
        <button onclick="w">结果</button> -->
    <!-- </script> -->

   <!-- <input type="text" id="a">+
   <input type="text" id="b">=
   <span id="c">0</span>
   <button onclick="d()">结果</button>
   <script>
       function d(){
           var a=document.getElementById("a").value;
           var b=document.getElementById("b").value;
           var c=document.getElementById("c");
           c.innerText=eval(a+"+"+b);
       }


   </script> -->

   <!-- <input type="text" id="a">-
   <input type="text" id="b">=
   <span id="c">0</span>
   <button onclick="d()">结果</button>

   <script>
       function d(){
           var a=document.getElementById("a").value;
           var b=document.getElementById("b").value;
           var c=document.getElementById("c");
           c.innerText=eval(a+"-"+b);
           
           
       }

   </script> -->

            <!-- <input type="text" id="a">-
            <input type="text" id="b">=
            <span id="c">0</span>
            <button onclick="d()">结果</button>
            <script>
                function d(){
                    var a=document.getElementById("a").value;
                    var b=document.getElementById("b").value;
                    var c=document.getElementById("c");
                    c.innerText=eval(a+"-"+b);
                }


            </script> -->
            <!-- <input type="text" id="a">*
            <input type="text" id="b">=
            <span id="c">0</span>
            <button onclick="d()">结果</button>
            <script>
                function d(){
                    var a=document.getElementById("a").value;
                    var b=document.getElementById("b").value;
                    var c=document.getElementById("c");
                    c.innerText=eval(a+"*"+b);
                }


            </script> -->
            <input type="text" id="a">/
            <input type="text" id="b">=
            <span id="c">0</span>
            <button onclick="d()">结果</button>
            <script>
                function d(){
                    var a=document.getElementById("a").value;
                    var b=document.getElementById("b").value;
                    var c=document.getElementById("c");
                    c.innerText=eval(a+"/"+b);
                }


            </script>

</body>

</html>